This invention relates to a process for the production of broken down cellulose copolymers utilizing a water soluble broken down cellulose polymer and a polysubstituted organic compound in an aqueous solution which are reacted to produce a broken down cellulose copolymer which may be in the form of a fine precipitated or as an aqueous dispersion.
The products produced by this invention have many commercial uses and may be utilized as molding powder, as coating agents for wood and metal, as films, as fillers, as impregnating agents, as adhesives, as binders, as caulking material, as fibers, as sheets, as casting materials, as putty material and may be further reacted with organic compounds to produce useful resinous products and foams.
A broken down cellulose copolymer is obtained by reacting the following components:
Component (a) broken down alkali metal cellulose polymer;
Component (b) an organic compound having at least two carbon atoms, each of which is attached to a substituent which will split off during the reaction;
Component (c) optionally, a solvent;
Component (d) optionally, an emulsifying or dispersion agent.
Component (a)
Component (a), a broken down alkali metal cellulose product, is produced by the processes outlined in my copending U.S. Patent Application, Ser. No. 013,139, filed Feb. 21, 1979 and is incorporated into this invention.
Water soluble, broken down, alkali metal cellulose polymers are produced by mixing 3 parts by weight of a cellulose-containing plant or plant derivative and 2 to 5 parts by weight of an alkali metal hydroxide, then heating the mixture at 150.degree. C. to 220.degree. C. while agitating for 5 to 60 minutes.
Any suitable plant or the products of plants which contain cellulose may be used in this invention. The plant material is preferred to be in the form of small dry particles such as sawdust. Suitable plants include, but are not limited to, trees, bushes, agricultural plants, weeds, vines, straw, flowers, kelp, algae and mixtures thereof. Wood is the preferred plant. Commercial and agricultural waste products may be used, such as stalks, paper, cotton clothes, bagasses, etc. Wood fibers (wood pulp) with lignin removed may be used in this invention. Plants that have been partially decomposed, such as humus, peat, certain soft brown coal, manure containing cellulose, etc., may also be used in this invention.
Any suitable alkali metal hydroxide may be used in this invention. Suitable alkali metal hydroxides include sodium hydroxide, potassium hydroxide and mixtures thereof. Sodium hydroxide is the preferred alkali metal hydroxide.
The novel broken down water soluble alkali metal cellulose polymer produced by the process of this invention differs from the alkali cellulose polymers produced by the known processes. The broken down alkali metal cellulose polymer is dark brown to black in color, has at least one --COH radical removed from each cellulose molecule, the usual lignin-cellulose bond is not broken in most of the cases and the cellulose molecules are broken down into smaller molecules of alkali metal broken down cellulose which are water soluble. When a cellulose polymer such as cotton or wood with the lignin removed is reacted with an alkali metal hydroxide by the process of this invention a black water soluble broken down alkali metal cellulose polymer is produced; this polymer may be reacted with a mineral acid until the pH is about 6 and a black, foamed broken down cellulose resinous product is produced. The foam is produced by the release of CO.sub.2 which was removed from the cellulose polymer. When a mineral acid is added to an aqueous solution of the broken down alkali metal cellulose polymer until the pH is about 6 a black resinous product floats to the top and recovered.
Compound (b)
Any suitable organic compound that will react with the broken down alkali metal cellulose polymer may be used. An organic compound is preferred, having at least two carbon atoms, of which one is attached to a substituent, which are split off during the reaction. These organic compounds which are the reactants used in the preparation of broken down cellulose copolymers have the graphical skeleton carbon structure of EQU X--C--C--X
where EQU --C--C--
represents two adjacent carbon atoms, or EQU X--C--R--CX
where X and X represent the substituents which split off during the reaction. The R between the pair of reactive carbon atoms is selected from the following groups: saturated straight chain carbon atoms, unsaturated carbon atoms, ether linkages, aromatic structures, and others, for it is to be understood that other intervening structures may be employed. The X and X substituents can be halogen, acid sulfate, nitrate, acid phosphate, bicarbonate, formate, acetate, propionate, laurate, oleate, stearate, oxalate, acid malonate, acid tartrate, acid citrate and others. Examples of these organic compounds include, but are not limited to:
__________________________________________________________________________ CH.sub.3 CHXOCHX'CH.sub.3 .alpha..alpha.' disubstituted ethyl ether; XC.sub.2 H.sub.4 OC.sub.2 H.sub.4 X' .beta..beta.' disubstituted ethyl ether; XCH.sub.2 OCH.sub.2 X' Disubstituted methyl ether; XC.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2 H.sub.4 X' Disubstituted ethoxy ethyl ether; XCH.sub.2 CH.sub.2 SCH.sub.2 CH.sub.2 X Disubstituted thio ethyl ether; ##STR1## Disubstituted 1,3 methoxy 2,2, dimethyl propane; XCH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.2 OCH.sub.2 CH.sub.2 CH.sub.2 Disubstituted dipropyl formal; ##STR2## Disubstituted para-diethoxy benzene; ##STR3## Disubstituted dimethoxy ethane; ##STR4## Disubstituted diethyl carbonate; ##STR5## Disubstituted glycol diacetate; ##STR6## pp' Disubstituted dibenzyl ether; ##STR7## pp' Disubstituted diphenyl ether; XCH.sub.2 CH.sub.2 SO.sub.2 CH:CH.sub.2 X' Disubstituted diethyl sulphone; ##STR8## .alpha..alpha.' Disubstituted propyl ether; ##STR9## Para Disubstituted benzene; ##STR10## Disubstituted para xylene; ##STR11## pp' Disubstituted dibenzyl; ##STR12## Disubstituted para hexyl propyl benzene; ##STR13## Disubstituted 3 toyl propene 2; __________________________________________________________________________
and others such as methylene chloride or bromide, ethylene dichloride, ethylene dibromide, propylene dichloride or dibromide, halohydrins, epihalohydrins, dihalides of unsaturated hydrocarbon gases derived from pressure-cracking processes, natural gas-cracking processes as well as compounds having more than two substituents such as 1,1,2 trichloroethane; 1,2,4 trichlorobutane; 1,2,3,4 tetrachlorobutane; trichloromesitylene and the like. Mixtures of these compounds may be used in this process.
Component (c)
Any suitable inorganic or organic solvent may be used in this invention. Suitable solvents include but not limited to water, alcohols, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, propyl alcohol; polyhydroxy organic compounds (polyols) such as ethylene glycol, propylene-1,2 and -1,3-glycol, butylene-1,4-and -2,3-glycol, hexane-1,6-diol, 2-methyl-propane-1,3-diol, glycerol, trimethylol propane, hexane-1,2,6-triol, butane-1,2,4-triol, trimethylol ethane, pentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dilintylene glycol, polybutylene glycols; polyesters, polyethers, sucrose polyethers and sucrose amine polyethers with at least 2, generally from 2 to 8 hydroxyl groups per molecule; and mixtures thereof.
Component (d)
Emulsifying or dispersing agents may be used in this invention, any salt-stable compound which is highly hydrophobous in nature and has a hydrophobic group as one component and a hydrophilic group as the other may be used. The emulsifying or dispersing agent which may be used for the formation of lattices of small-particle size are those compounds having such groups as SO.sub.3, SO.sub.4, NH.sub.2, etc., as the hydrophilic component and a higher molecular weight alkyl, aralkyl, aryl or alkyl group as the hydrophobic component. The mere hydrophobic the entire compound becomes, the smaller the polymer particle size becomes in the latex.
Compounds which are most suitable as emulsifying or dispersing agents for latex formation are the lignin sulfonates such as calcium and sodium lignin sulfonates, alkyl benzene sulfonates having more than 20 carbon atoms in the alkyl group, aryl alkyl sulfonates, sorbitan monolaurates, especially those which are oil soluble and slightly water soluble, and others. The dominance of the hydrophobic group over the hydrophilic groups is one of the important factors in producing a latex of small-particle size. The molecular weight of the hydrophobic group alone is not the deciding factor, for aryl groups, for example, may be more hydrophobic than an alkyl group of like molecular weight. Aryl alkyl groups are more hydrophobic than alkyl aryl groups of the same molecular weight. Thus by selection of emulsifying or dispersing agents, the particle size of the latex can be varied to suit any particular needs. Emulsifiers which can be used are sorbitan monolaurates, alkyl aryl sulfonates, alkyl aryl sulfates, aryl alkyl sulfonates, aryl alkyl sulfates, lignin sulfonates, methyl cellulose, sulfonated petroleum fractions, polymerized alkyl aryl sulfonates, polymerized aryl alkyl sulfonates, soybean lecithin, and the like. The particle size can be controlled by selecting emulsifying or dispersing agents having different molecular-weight hydrophobic groups as well as different hydrophobic groups. The particle size will also vary with the concentration of the emulsifying or dispersing agents.
In certain cases, other dispersing agents such as magnesium hydroxide or aqueous dispersions of peptized starch, gelatin, glue, blood-albumen, egg albumen, or the like, may be used.
The primary object of this invention is to produce broken down cellulose copolymers. Another object is to produce broken down cellulose copolymer that may be used as molding powder, as coating agents for wood and metal, as films, as filters, as impregnating agents, as adhesives, etc. Another object is to produce broken down cellulose copolymers which will react with polyisocyanates to produce foam which may be utilized as thermal and sound insulation. Still another object is to produce polysulfide broken down cellulose copolymers. Still another object is to produce polysulfide-silicate-broken down cellulose copolymers. Still another object is to produce aldehyde-broken down cellulose copolymers.